Distinguish between deductive and inductive arguments.
Understand the terms valid, invalid, and sound.
Understand the terms strong, weak, and cogent.
Judging Arguments
Be able to follow the four-step procedure for determining whether an argument is deductive or inductive, good or bad.
Be familiar with indicator words that suggest that an argument is deductive or inductive.
Finding Missing Parts
Know how to use the three-step procedure for uncovering implicit premises.
Argument Patterns
Memorize and be able to recognize the argument patterns know as modus ponens, modus tollens, hypothetical syllogism, denying the antecedent, affirming the consequent, and disjunctive syllogism.
Be able to use the counterexample method for determining if a deductive argument is valid or invalid.
Diagramming Arguments
Understand the definition of dependent and independent premises.
Be able to follow the five-step procedure to diagram arguments, both simple and complex ones, including those embedded in extraneous material.
Assessing Long Arguments
Understand the challenges involved in assessing long arguments.
Be able to follow the four-step procedure for diagramming long arguments.
Chapter summary
Arguments come in two forms: deductive and inductive. A deductive argument is intended to provide logically conclusive support for a conclusion; an inductive one, probable support for a conclusion. Deductive arguments can be valid or invalid; inductive arguments, strong or weak. A valid argument with true premises is said to be sound. A strong argument with true premises is said to be cogent.
Evaluating an argument is the most important skill of critical thinking. It involves finding the conclusion and premises, checking to see if the argument is deductive or inductive, determining its validity or strength, and discovering if the premises are true or false. Sometimes you also have to ferret out implicit, or unstated, premises.
Arguments can come in certain common patterns, or forms. Two valid forms that you will often run into are modus ponens (affirming the antecedent) and modus tollens (denying the consequent). Two common invalid forms are denying the antecedent and affirming the consequent.
Analyzing the structure of arguments is easier if you diagram them. Argument diagrams can help you visualize the function of premises and conclusions and the relationships among complex arguments with several subarguments.
Assessing very long arguments can be challenging because they may contain lots of verbiage but few or no arguments, and many premises can be implicit. Evaluating long arguments, though, requires the same basic steps as assessing short ones:
(1) Ensure that you understand the argument,
(2) locate the conclusion,
(3) find the premises, and
(4) diagram it to clarify logical relationships.
Chapter 03
Chapter Objectives
Argument Basics
Judging Arguments
Finding Missing Parts
Argument Patterns
Diagramming Arguments
Assessing Long Arguments
Chapter summary
Arguments come in two forms: deductive and inductive. A deductive argument is intended to provide logically conclusive support for a conclusion; an inductive one, probable support for a conclusion. Deductive arguments can be valid or invalid; inductive arguments, strong or weak. A valid argument with true premises is said to be sound. A strong argument with true premises is said to be cogent.
Evaluating an argument is the most important skill of critical thinking. It involves finding the conclusion and premises, checking to see if the argument is deductive or inductive, determining its validity or strength, and discovering if the premises are true or false. Sometimes you also have to ferret out implicit, or unstated, premises.
Arguments can come in certain common patterns, or forms. Two valid forms that you will often run into are modus ponens (affirming the antecedent) and modus tollens (denying the consequent). Two common invalid forms are denying the antecedent and affirming the consequent.
Analyzing the structure of arguments is easier if you diagram them. Argument diagrams can help you visualize the function of premises and conclusions and the relationships among complex arguments with several subarguments.
Assessing very long arguments can be challenging because they may contain lots of verbiage but few or no arguments, and many premises can be implicit. Evaluating long arguments, though, requires the same basic steps as assessing short ones:
(1) Ensure that you understand the argument,
(2) locate the conclusion,
(3) find the premises, and
(4) diagram it to clarify logical relationships.